The objective is to modify collagen to increase and control the resorption time in implants without causing inflammation. The specific aim is to develop a collagen membrane for periodontal use with a resorption time of about twelve weeks and negligible inflammatory response. A noninflammatory long resorption time collagen would also find application in orthopedics, breast implantation, controlled drug delivery, surgical procedures requiring resorbable hemostats, sutures, etc., and related fields. Crosslinking collagen with glutaraldehyde increases resorption time, but the crosslinked product also causes inflammation. Conjugation with alkaline phosphatase, however, increases resorption time without causing inflammation. Electron microscopy shows that the enzyme conjugation produces a smoother, more regular and organized surface. Enzyme conjugation also increased water sorption, while crosslinking decreased it. The following tests will be carried out on discs made of four types of collagen: untreated, crosslinked, enzyme-conjugated, and crosslinked enzyme-conjugated. 1) Water sorption. 2) Residual alkaline phosphatase activity. 3) Degradation with collagenase (as an indication of eventual resorption). 4) Measurements of membrane thickness and mechanical properties. 5) Histopathological examination of the tissues surrounding subcutaneous implants of the discs in rats, removed periodically for inflammation levels and residual collagen.